Strict glycemic control is associated with better outcomes in type 1 diabetes, but few patients alter their daily insulin dosage appropriately to maintain ideal blood glucose levels relative to calorie intake. Studies of strict glycemic control have required the intensive use of health resources and reported an increased risk of hypoglycemic reactions and a lowered quality of life. In one alternative approach, patients are given intensive education about matching insulin dosages to food and lifestyle choices. Heller and colleagues studied the effect of using dosage adjustment for normal eating (DAFNE) to manage type 1 diabetes in patients attending hospital diabetic clinics in two English cities.
The 169 study participants (mean age, 40 years) had moderately to poorly controlled type 1 diabetes, with average glycosylated hemoglobin (HbA1c) levels of 7.5 to 12.0 percent for more than two years but no evidence of advanced complications. The participants were randomly assigned to attend DAFNE training immediately or after usual care for six months. The delayed-DAFNE group acted as control subjects in the initial analysis of outcomes.
DAFNE training consisted of a five-day out-patient program on matching insulin dosages to desired carbohydrate intake, meal by meal. The principal outcomes measured were HbA1c levels, patient-reported hypoglycemic episodes (i.e., episodes resulting in coma or requiring assistance from another person), and the findings of a standardized diabetes-specific quality-of-life questionnaire. Other aspects monitored included the number of insulin injections and the amount of insulin used, frequency of hyperglycemia, psychologic well-being, changes in weight, blood pressure, cholesterol levels, and blood lipid values.
Complete data were available for 140 patients who took DAFNE education immediately and 68 patients who had delayed DAFNE education. After six months, HbA1c levels were significantly improved in the immediate-DAFNE group, but no significant difference was found in hypoglycemic episodes (see the accompanying table). Patients in the immediate-DAFNE group also reported significant improvements in quality of life, specifically, the impact of diabetes on dietary freedom. At 12 months, HbA1c levels remained significantly improved, and the beneficial impact on quality of life and dietary freedom was maintained.
The authors conclude that patients with type 1 diabetes who underwent dietary skills training were better able to follow intensive insulin therapy over the short term and had sustained improvement in glycemic control without an associated increase in hypoglycemic episodes.